Recent years have witnessed a problematic act of illegally obtaining works, such as a book, in the form of electronic data with use of a digital camera or a mobile terminal device such as a mobile telephone that is equipped with a camera and that thus has a digital camera function. An example of such an act is the act of photographing works such as a photograph and text in a book with use of a camera-equipped mobile telephone in a store without purchasing the book.
Patent Literatures 1 and 2, for example, each disclose a technique for preventing such illegal acts. Patent Literature 1 discloses a technique of (i) providing a transmitter at a place targeted for prohibition of camera photography and (ii) in the case where a camera-equipped mobile telephone enters a communication area of the transmitter, causing the camera-equipped mobile telephone to disable its camera photography function upon receipt of a control signal outputted from the transmitter.
Patent Literature 2 discloses a technique of changing a level of camera photography (recording permitted, recording limitedly permitted, or recording prohibited) in correspondence with the recording mode of the digital camera (still image recording, moving image recording, or audio recording). This technique, for instance, permits audio recording, limitedly permits still image recording, and prohibits moving image recording.
The above techniques can each prevent works from being illegal obtained.
Japanese Patent Application Publication, Tokukai, No. 2005-341044 A (Publication Date: Jan. 28, 2005)
Japanese Patent Application Publication, Tokukai, No. 2008-78845 A (Publication Date: Apr. 3, 2008)